Heat exchange for continuous throughflow of two media



HEAT EXCHANGE FOR CONTINUOUS THROUGHFLOW OF TWO MEDIA Filed Jan. 24,1956 Nov. 28, 1961 M. MAUTNER ETAL 2 Sheets-Sheet 1 9 L M a U w M 8 2 IO I Y A .15 1 m w E 8 6 ,A/M I4, I I Win95 m iiflllllll In \I BY AWM WATTORNEYS Nov. 28, 1961 MAUTNER ETAL HEAT EXCHANGE FOR CONTINUOUSTHROUGHFLOW OF TWO MEDIA Filed Jan. 24, 1956 2 Sheets-Sheet 2 Fig.3

United States Patent 3,010,702 HEAT EXCHANGE FOR CONTINUOUS THROUGH-FLOW OF TWO NIEDIA Mihailo Mautner, Milenko Flego, and Zvonimir Geric,Zagreb, Yugoslavia, assiguors to Aktiebolaget Separator, StoMolm,Sweden, a corporation of Sweden Filed Jan. 24, 1956, Ser. No. 561,017Claims priority, application Yugoslavia Feb. 16, 1955 6 Claims. (Cl.257-241) The present invention relates to a heat exchanger adapted forcontinuous throughflow of two media during the heat exchange operationand which comprises a hollow, single-walled rotor provided with an inletand an outlet for one medium, and a closed housing surrounding the rotorand having an inlet and an outlet for the other medium.

In a heat exchanger made according to the invention, the hollow of therotor is kept separate from the hollow of the surrounding housing bymeans of sealing devices; the inlet of the rotor opens into the hollowof the rotor at one end of the rotor; at paring device is arranged inthe outlet of the rotor at the other end of the rotor; and the inlet andoutlet of the rotor are so arranged that the first medium passes throughthe rotor from its inlet to its outlet in a relatively .thin layerspread over the surface of the rotor wall. The latter feature involves acertain dimensioning of the inlet and outlet and also location of theparing device at a suitable distance from the center of the rotor.

The apparatus of the invention can be used for various kinds ofoperations, such as evaporation with or without vacuum, vaporization,deodorization of vegetable oils, redistillation of aromaticrand etherialoils, vacuum distillation of all kinds (eg partial distillation,selective distillation, etc.), and cooling.

For a better understanding of the invention, reference may be had to theaccompanying drawings, in which:

FIG. 1 is a vertical sectional view of a preferred form of the newapparatus;

FIGS. 2, 3 and 4, are vertical sectional views of modifled forms of therotor body shown in FIG. 1', and

FIG. is a vertical sectional view of a modified form of the device forsupplying one of the fluid media which are passed through the heatexchanger.

Referring to FIG. 1, the heat exchanger there shown comprises a hollowrotor 1 surrounded by a housing 2. The rotor i is provided at its endswith hollow pivots or trunnions 3 and 4 by means of which it isrotatably mounted in ball bearings 5 and 6. The upper bearing 5 isfitted in a neck-like extension 7 of the surrounding housing 2, and thelower bearing 6 is fitted in a sleeve 8 in a frame 9 supporting thishousing. The hollow of the rotor i is kept separate from the surroundinghousing 2 by sealing means it The latter, as illustrated in FIG. 1,comprise elastic rings 19:: closely surrounding the upper trunnion 3 andsecured to metal rings which fit closely in the neck 7 above and belowthe bearing 5.

The rotor is provided with a central stationary feed pipe 11 whichextends through the upper trunnion 3 into the interior of the rotor andforms an inlet which opens into the lower end of the rotor. The rotoralso contains a stationary paring device 12, the entrance or mouth ofwhich is located in a widened part of the hollow of the rotor at itsupper end, the rotor having substantially the form of a truncated cone.The paring device 12 forms an outlet connected with a stationarydischarge pipe 13 extending through the lower trunnion 4, which passesthrough a central opening in the lower end portion 15 of the surroundinghousing 2. The clearance between the lower trunnion 4 and the edge ofthis central opening isclosed by a sealing device 14. The housing 2 hasat although the generatrix may take other forms.

3,010,702 Patented Nov. 28, 1961 "ice its upper part an inlet 16 and atits bottom an outlet 17. The hollow of the rotor may communicate with asuction device through the channel in the upper trunnion 3 and an outlet18.

The rotor is driven by means of a on the lower trunnion 4. The space nelin this trunnion 4 and the discharge pipe by means of a sealing device20. The rotor is at its upper end with one or more conveyor vanes whichextend generally radially of the rotor axis.

When the heat exchanger is used for evaporation purposes, for example,the heat-emitting medium, which may consist of steam, is suppliedthrough the inlet 16. The heat-absorbing medium is introduced throughthe pipe 11 into the lower part of the rotor 1 and is spread in arelatively thin layer over the conical wall of the rotor. Under theinfluence of the centrifugal force resulting from the rotation of therotor, the heat-absorbing medium passes towards the upper part of thehollow of the rotor and is there pared out by the paring device 12. Theheat-emitting medium may be condensed by contact with the outside of therotor, and the resulting condensate is immediately thrown away from therotor wall by the influence of the centrifugal force. This condensate iscollected at the bottom of the housing 2 and is discharged through theoutlet 17, which may be connected with a condensate pump (not shown) orconsist of a steam trap. As a result of the rotation of the rotor, thereis thus obtained a high heat transfer coefiicient between theheatemitting medium and the rotor wall, partly because of the velocitygradient in the heat-emitting medium and partly because, as previouslymentioned, any condensate formed on the rotor wall is the rotor Wall. Ina similar manner, a high heat-transfer coefficient is obtained on theinside of the rotor between the rotor wall and the heat-absorbingmedium, since by adjusting the speed of rotation of the rotor and thethroughflow rate, the velocity of this medium can be kept relativelyhigh on the inside of the rotor wall, and any gases or vapors which maybe present in the heat-absorbing medium and which are released, forinstance, by evaporation, can be rapidly separated out or be removedthrough the influence of the centrifugal force. These gases or vaporsare discharged through the channel in the trunnion 3 and the outlet 18,which form a suction line leading from the interior of the rotor 1. Itis evident that by connecting the outlet 18 with a vacuum pump, or thelike, it is possible to obtain a sub-atmospheric pressure in the hollowrotor, whereby the evaporation can take place at the temperature mostsuitable to each individual case.

The rotor 1 of the heat exchanger shown in FIG. 1 has substantially theform of a truncated cone, the lateral surface of which is formed by arectilinear generatrix,

According to FIG. 2, the generatrix is bent so that the diameter of therotor 1 increases slowly at the lower end 1a of the rotor, where thematerial which passes through the hollow of the rotor is introduced, butincreases more rapidly at the opposite end 1b where the material isdischarged. This can be of advantage in the treatment of certain kindsof material, since it enables control of the axial flow velocity of themedium so that this velocity is either changed or is kept constant inspite of the fact that the viscosity increases through the evaporationof the medium. In certain cases it is desirable that the diameter of therotor vary as shown in FIG. 3, where the diameter at the two ends 1a and1b of the rotor changes relatively slowly in the longitudinal directionof the rotor, while between the ends of the rotor there is a zone 1cwhere the diameter of the rotor changes more rapidly.

An enlargement of the heat-transmitting area can be pulley 19 arrangedbetween the chan- 13 is closed provided 21,

immediately thrown out from dium, the rotor wall forming a surfacerounding the rotor, in the form of jets directed straight toward theoutside of the rotor or in jets which are more or less tangential to therotor. The distributing tubes 22 may be connected to a common feed pipe25 vided with a connecting flange 2'4.

. We claim: 1. In aheat exchanger adapted for continuous throughduringheat exchange operation, the

suitably pr-' through the 7 said pipes forming an inlet fortheheat-absorbing medium 7 and opening-into the rotor at said small endthereof, a

paring device located in said large end of the rotor at the outer partthereof and forming an outlet from which the other pipe leads todischarge the heat-absorbing meover which the a screw or spiral. Suchheat-absorbing medium passes in a thin layer through the rotor from saidsmall inlet end to the large outlet end thereof, one of said trunnionsforming with the corresponding pipe an annular passage leading from therotor, and a suction line leading from said annular passage forevacuating gases emitted from said thin layer of the heatabsorbingmedium.

2. The combination according to claim 1, in which said inlets andoutlets of said space and the rotor are positioned for counter-currentflow of said two media. a

3. The combination according to claim 1, in which the rotor wall iscorrugated.

4. The combination according to claim 1, in which said space inlet forthe heat-emitting medium includes nozzles opening into the housingadjacent the rotor and arranged to direct jets of said heat-emittingmedium against the outside of the rotor.

5. The combination according to claim 1, in which said space inlet forthe heat-emitting medium includes nozzles opening into the housingadjacent the rotor and arranged to direct'jets of said heat-emittingmedium against the outside of the rotor, and distribution tubes to whichthe nozzles are connected. V

6. The combination according to claim 1, comprising also a seal betweenthe other of said trunnions and the communication between the interiorof the rotor and atmosphere through said trun- References Cited in thefile of this patent ITED STATES PATENTS 570,737 Sharples Nov. 3, 825,721Hartmann July 10, 1906 879,490 Rasmussen Feb. 18, 1908 1,004,760 Fetz'erOct. 3, 1911 1,093,500 Todt Apr. 14, 1914 1,701,777 Jensen Feb. 12, 19291,930,479 Jones Oct. 17, 1933 2,067,273 Knowles et al. Jan. 12, 19372,119,907 Dunlap June 7, 1938 2,169,601 Cornelius et a1 Aug. 5, 19392,318,293 Cornell May 4, 1943 FOREIGN PATENTS 146,391 Australia Sept. 6,1951

